Use of Model-Informed Drug Development to Streamline Development of Long-Acting Products: Can These Successes Be Translated to Long-Acting Hormonal Contraceptives?

Considerations for the Use of Long-Acting and Extended-Release Agents During Pregnancy and Lactation

Long-acting agents hold significant promise for treating and preventing common illnesses, including infections. Pharmacokinetic and safety data during pregnancy and lactation are often unavailable for new drugs; these data are vital to facilitate optimal drug use by pregnant and lactating women and women who may conceive. In this commentary, we summarize the circumstances in which pregnant and lactating women are likely to use and benefit from long-acting agents. We focus on long-acting formulations of small molecules (rather than biologics such as monoclonal antibodies) and on several infections of global importance (human immunodeficiency virus, tuberculosis, malaria, and hepatitis C). We discuss pregnancy pharmacokinetic/pharmacodynamic and potential safety and efficacy considerations pertaining to the use of long-acting agents in pregnancy and lactation. Finally, we summarize existing preclinical and pregnancy pharmacokinetic data that are available (or expected in the near future) for several agents that are under development or approved, and how key research gaps may be addressed.

A Holistic Review of the Preclinical Landscape for Long-Acting Anti-infective Drugs Using HIV as a Paradigm

Lack of predictive preclinical models is a key contributor to the steep attrition rate in drug development. Successful clinical translation may be higher for new chemical entities or existing approved drugs reformulated for long-acting (LA) administration if preclinical studies designed to identify any new uncertainties are predictive of human exposure and response. In this review, we present an overview of standard preclinical assessments deployed for LA formulations and delivery systems, using human immunodeficiency virus LA therapeutics preclinical development as a paradigm. Key progress in the preclinical development of novel LA antiretrovirals formulations and delivery systems are summarized, including bispecific broadly neutralizing monoclonal antibody and small molecule technologies for codelivery of multiple drugs with disparate solubility properties. There are new opportunities to take advantage of recent developments in tissue engineering and 3-dimensional in vitro modeling to advance preclinical modeling of anti-infective activity, developmental and reproductive toxicity assessment, and to apply quantitative modeling and simulation strategies. These developments are likely to drive the progression of more LA anti-infective drugs and multipurpose technologies into clinical development in the coming years.

Barriers for multiparous women to using long-term contraceptive methods in Southeast Asia: case study in Philippines and Indonesia

Background

Multiparous women are supposed to be able to end their reproductive cycle to decrease population growth. This study aimed to analyze barriers for multiparous women to use long-term contraceptive methods (LTCM) in the Philippines and Indonesia.

Methods

The study population was women aged 15–49 years old who have given birth to a live baby > 1 in the Philippines and Indonesia. The weighted sample size was 12,085 Philippines women and 25,543 Indonesian women. To identify variables associated with the use of LTCM, we analyzed place of residence, age group, education level, marital status, employment status, and wealth status. The final step employed multinomial logistic regression.

Results

In both countries, the results showed that variables associated with non-user LTCM were younger women, living in rural areas with poor education. Women without partner and unemployed had higher probability to not use LTCM. Finally, low wealth status had a higher probability than the richest multiparous to not use LTCM.

Conclusion

The study concluded that there were six barriers for multiparous women to use LTCM in the Philippines and Indonesia. The six obstacles were living in rural areas, being younger, poor education, single, unemployed, and low wealth.

Application of exposure bracketing to streamline the development of contraceptive products

Developing new long-acting products of well-characterized contraceptive drugs is one way to address some of the reasons for unmet need for modern methods of family planning among women in low- and middle-income countries. Development and approval of such products traditionally follow a conventional paradigm that includes large Phase 3 clinical trials to evaluate efficacy (pregnancy prevention) and safety of the investigational product. Exposure-bracketing is a concept that applies known pharmacokinetics and pharmacodynamics of a drug substance to inform its safe and efficacious use in humans. Several therapeutic areas have applied this concept by leveraging established drug concentration-response relationships for approved products to expedite development and shorten the timeline for the approval of an investigational product containing the same drug substance. Based on discussions at a workshop hosted by the Bill & Melinda Gates Foundation in December 2020, it appears feasible to apply exposure-bracketing to develop novel contraceptive products using well-characterized drugs.

An Integrated Pharmacokinetic-Pharmacodynamic-Pharmacoeconomic Modeling Method to Evaluate Treatments for Adults with Schizophrenia

INTRODUCTION

Schizophrenia is a chronic mental disorder that worsens with each relapse. Long-acting injectable (LAI) antipsychotics may prevent the exacerbation of symptoms and occurrence of relapses through improved continuity of care. Different dose regimens are available for the LAIs aripiprazole monohydrate (AM) and aripiprazole lauroxil (AL), but their cost effectiveness is unclear.

OBJECTIVES

The study aim was to compare costs and effects (relapses) of the different aripiprazole LAI dose regimens to inform clinical and US payer decisions.

METHODS

A state-transition model calculated the outcomes of eight LAI dose regimens based on their relapse rates. As effectiveness data from randomized controlled trials were unavailable, relapse rates were modeled using pharmacokinetic and pharmacodynamic evidence. These described blood plasma levels of aripiprazole as a function of AM and AL dose regimens and described the probability of relapse as a function of aripiprazole blood plasma levels. The analysis had a time horizon of 1 year and took the US healthcare payer perspective. The incremental cost per relapse avoided and the probability of cost effectiveness were calculated in deterministic and probabilistic analyses. Scenario analyses explored the model's main assumptions, and results were validated against external data and other cost-effectiveness analyses.

RESULTS

Monthly administration of AM 400 mg consistently yielded the lowest predicted number of relapses across deterministic, probabilistic, and scenario analyses. The costs of treatment and relapses were projected to be the lowest with a monthly administration of AL 441 mg. The incremental cost per relapse avoided with AM 400 mg ranged from AM 400 mg being dominant to $US83,300. From willingness-to-pay thresholds of $US30,000 per relapse avoided, the probability of cost effectiveness was highest for AM 400 mg. The validation showed alignment with external data.

CONCLUSION

The analysis highlighted the robustness of the novel framework based on pharmacokinetic and pharmacodynamic evidence and demonstrated an application in a postmarketing setting.